Ultimate Guide to Hair Trimmer Guard Sizes

Choosing the right guard takes guesswork out of haircuts. This simple guide explains hair trimmer guard sizes, shows an easy inches-to-mm chart, and helps you pick the right length for buzz cuts, crew cuts, tapers, and trims. We’ll also cover hair trimmer guard sizes in mm, half-guards, and quick tips so your results look even—every time.

What a guard does (and why numbers matter)

Clipper guards (aka guide combs) set a fixed cutting length by covering the blade with a plastic or metal comb at a known height. Guard numbers (e.g., #2, #4) map to approximate lengths. Lower number = shorter hair left; higher number = longer hair. For a quick primer on how clippers work, see this neutral overview of the hair clipper.

Hair trimmer guard sizes chart (inches ↔ mm)

Lengths vary slightly by brand and blade geometry. Use these as common industry approximations.

Half-guards (like #0.5 or #1.5) are blending heroes—great for melting hard lines between steps.

How to pick the right guard (by goal)

• Even buzz cut: start #4 for safe length; drop to #3 or #2 if you want closer.
• Classic short back & sides: sides #2–#3, top #4–#6.
• Beginner fade: bottom #1, mid #2, near top #3, then blend with #1.5.
• Kids or longer trims: keep tops #6–#8, sides #3–#4 for a soft look.

Unsure? Start longer. You can always go shorter; you can’t put hair back.

Guard sizes in mm vs inches (and why they differ a bit)

Manufacturers round to friendly numbers (e.g., 1/2″ ≈ 12.7 mm → listed as 13 mm). The blade’s curvature and the taper lever also affect real-world length. That’s why two brands’ “#4” can look a hair different. If you want precision, think in mm and stick with the same brand once you like a look. For unit background: inch and millimetre.

The taper lever cheat code (micro-adjustments)

Your clipper’s taper lever fine-tunes length without changing guards:

• Lever open = slightly longer (adds ~0.5–1 mm depending on the model).
• Lever closed = slightly shorter.
  Use it to blend lines between guards or to soften heavy spots around the ridge.

When to use half-guards

If you see a visible “step” between, say, #1 and #2, pop on a #1.5 with the lever open and feather just on the line with short, flick-out strokes. Half-guards save time and keep blends velvety.

Guard materials: standard vs premium

• Standard plastic guards: light, budget-friendly, good for home use.
• Premium/magnetic guards: more rigid; they track hair better and can reduce chatter.
• Metal clip inserts: improve grip on the blade shoe and reduce pop-off during fast passes

Guard sizes vs. trimmers vs. shavers (what to grab when)

• Clipper + guards: main tool for bulk cuts and set lengths from ~1.5–25 mm.
• Beard trimmer: best for facial hair, edging, and shorter stubble control. Learn more about facial hair basics via this neutral beard overview.
• Foil/electric shaver: finishes closer than #0, ideal for bald fades and skin-close areas; see general electric shaver info.

If you’re building a starter kit, browse Hair Clippers for core tools and Hair Cutting Kits for guards, combs, and accessories in one box.

Mini how-to: use guards for clean, even results

• Start long (e.g., #4). Work against the grain, bottom to top, flicking out at the ridge.
• Step down one guard at a time to approach your target length.
• Blend the transition using half-guards and the lever open.
• Cross-check passes from a different direction to catch missed hairs.
• Clean & oil the blade every session to prevent tugging and uneven tracks. General irritation tips: see razor bumps basics.

Quick picks (Bestbomg fit, user-based)

• New to home cuts: go for an all-in-one kit so you have guards #1–#8 from day one—see Hair Cutting Kits.
• Want precision + runtime: cordless Hair Clippers with a strong motor and full guard set make blending easier and faster.

Frequently Asked Quetsions 

What guard size is best for a buzz cut?

A #3 (≈10 mm) is a popular “not too short” buzz. For closer, try #2 (6 mm) or #1 (3 mm). Start longer and drop if you want tighter.

What does a #4 guard look like in mm?

A #4 guard is 1/2″, which is about 13 mm. It’s a great top length for classic crew cuts and tidy trims.

What is a 1.5 guard in mm?

#1.5 is 3/16″, roughly 4.5 mm. It’s often used as a blend step between #1 (3 mm) and #2 (6 mm).

Are guard lengths the same across brands?

They’re close but not identical. Tolerances, blade curve, and lever position can shift the true cut. If you like a length, stick to the same brand for repeatable results.

Do I need half-guards to fade?

They help a lot. Half-guards (like #0.5 and #1.5) melt hard lines quickly and make beginner fades look cleaner with fewer passes.

Conclusion + CTA

Guards turn guesswork into repeatable lengths. Use the chart above, start long, and blend with half-guards and the lever. Ready to build a reliable setup? Explore Hair Clippers or grab everything in one box with Hair Cutting Kits.